[ale] Reading old XDF formatted floppies

[krwatson at cc.gatech.edu]

This might help.

Frequently asked question about the Linux floppy driver
http://fdutils.linux.lu/faq.html

How should I describe the Xdf formats in /etc/mtools?
http://fdutils.linux.lu/faq.html#mtools-xdf

keith

-- 

Keith R. Watson                        Georgia Institute of Technology
Systems Support Specialist IV          College of Computing
keith.watson at cc.gatech.edu             801 Atlantic Drive NW
(404) 385-7401                         Atlanta, GA  30332-0280

> -----Original Message-----
> From: ale-bounces at ale.org [mailto:ale-bounces at ale.org] On Behalf Of
> Michael B. Trausch
> Sent: Tuesday, October 06, 2009 14:27
> To: Atlanta Linux Enthusiasts - Yes! We run Linux!
> Subject: Re: [ale] Reading old XDF formatted floppies
> 
> On Tue, 2009-10-06 at 10:51 -0600, JK wrote:
> > Is this the OS/2 eXtended Disk Format, or the Emulators Inc Xformer
> > Disk Format?
> 
> It is IBM's XDF (eXtended Density Format).[1]
> 
> It would appear that fine-grained control of the FDC is required to read
> the media.  I thought to boot up PC DOS 7 to try to read it by loading
> the XDF.COM program after booting the OS, but it is also unable to read
> the disks in the USB floppy drive that I have.
> 
> Because XDF uses variable-sized tracks _and_ variable-sized disk
> sectors, attempting to read these disks in a device that only
> understands the traditional 1.44 MB floppy format (that is, eighteen
> 512-byte sectors per track, 80 tracks, 2 heads) won't work.
> 
> It looks like these are my options:
> 
>  * Find a way to tell my USB floppy drive how to read the XDF disks.
> The xdfcopy program in Linux can read these for normal floppy disk
> drives that are attached to an Intel 82072A (or compatible) floppy disk
> controller.
>  * Acquire a floppy disk drive that attaches to one of these standard
> controllers (as found on just about any motherboard).
> >
> > In either case, I'd start by dd-ing an image of the floppy to a local
> > file.  Then explore emulators or virtualized environments that
> > understand
> > that disk format.
> >
> > http://www.faqs.org/faqs/atari-8-bit/faq/section-85.html
> 
> Unfortunately, this will not work because XDF is a different physical
> (low-level) disk format, not a filesystem format.  Because of the
> different format of the disk, my current drive emits errors while
> reading the diskettes.  This makes sense, because the tracks cannot be
> found by the drive:
> 
> [ 8447.546504] sd 5:0:0:0: [sdg] Unhandled sense code
> [ 8447.546515] sd 5:0:0:0: [sdg] Result: hostbyte=DID_OK
> driverbyte=DRIVER_SENSE
> [ 8447.546524] sd 5:0:0:0: [sdg] Sense Key : Medium Error [current]
> [ 8447.546536] Info fld=0x8
> [ 8447.546539] sd 5:0:0:0: [sdg] Add. Sense: Recorded entity not found
> 
> The drive that I have is:
> 
> http://www.superwarehouse.com/SmartDisk_USB_Floppy_Drive_Titanium_Edition/
> FDUSB-TM2/p/284644
> 
> My (uneducated, at present) guess is that this drive (and other USB
> floppy drives) do not expose a low-level enough programming interface to
> be able to read media that is formatted in any format that isn't a
> standard format (which means XDF, 2M, etc), whereas a standard FDC can
> be programmed to read these formats from software.  I am trying to find
> programming information that would enable me to get access to the
> controller in this drive to see if I am able to read these disks then,
> but I'm not entirely sure that's going to even be possible.
> 
> What I'd really like to have is a super-programmable controller that
> lets software decide the encoding strategy for the disk (this would
> make it possible for me to read Apple formatted 400K and 800K disks,
> which the PC FDC cannot read since it does MFM encoding in hardware,
> and the aforementioned Apple-formatted disks use GCR and constant linear
> velocity instead of a static RPM for the drive.
> 
> It appears that the drive that I have is able to read Microsoft
> DMF-formatted floppy disks (that is, 80 sectors, 512-byte sectors, 21
> sectors per track) just fine, so it seems that the hardware does
> implement more than just the standard PC formats, but not things like
> XDF.  I do not have any 2M formatted floppies, but I probably cannot
> read those either without finer-grained control of the drive's built-in
> controller.
> 
> It looks as if the xdfcopy from fdutils uses ioctl calls to control the
> FDC while working with XDF formatted floppies.  But, USB mass storage
> devices (including floppy drives) do not expose a controller, so far as
> I'm aware.
> 
> 	--- Mike
> 
> --
> Blog:  http://mike.trausch.us/blog/
> Misc. Software:  http://mike.trausch.us/software/
> 
> "The greater danger for most of us lies not in setting our aim too
> high and falling short; but in setting our aim too low, and achieving
> our mark." -Michelangelo
> 
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